But the overwhelming sense was that activists don’t trust politicians – and want a real say in how change is made.

As Sydney put it, “Politicians want to be seen to be saying the right thing but the government is so hypocritical.”

Ann, who described herself as a “concerned citizen”, told Socialist Worker, “The government has revoked green policies in the building industry. They need to put them back and make them tighter – and they need to do it now.

Drew said she didn’t think the kind of change needed is possible in the current system. She said, “The thing that can make a difference is the big corporations.

“They make all the decisions about where to source things and what materials to use. But everyone’s just interested in money-making schemes.”

Disaster

Jim said that it is “probably too late” to stop “ecological disaster”. “But it just might not be if we act now,” he said. “It will take a complete change in the economy – we can’t keep capitalism the way it is now.”

This was a common theme. Guardian columnist Owen Jones told the crowd, “We’re not going to save the planet until we overthrow the system – and that system is called capitalism.”

There were lots of different ideas about how to do this, and some confusion. “I don’t know who will lead this,” said Drew. “But XR has shown that people can make a difference. It’s been really refreshing.”

Environmental activist Zack told Socialist Worker, “I don’t believe in the political structure. I think the government is a puppet of a larger political structure made up of the corporations and the elites.

“This is not about getting the message across to them – it’s about challenging them and taking action against them.”

Drew (right) said Extinction Rebellion "has shown that people can make a difference" (Pic: Socialist Worker)

The protest was backed by Labour left group Momentum, Youth Strike 4 Climate, Campaign Against Climate Change, Labour for a Green New Deal and People & Planet. Yet large numbers of protesters weren’t in any campaign group or political party.

The FBU firefighters’ union brought a fire engine to use as a stage, and provided a sound system. FBU general secretary Matt Wrack spoke to the crowd, and a small number of trade unionists joined the protest.

PCS union member Rhea said she came to show “solidarity” after a climate activist addressed a May Day rally in London earlier in the day. “These are common struggles,” she told Socialist Worker. “Working people are disproportionately affected by climate change.”

NEU union member and primary school teacher Fran added, “We can’t trust the government to deal with climate change. Businesses have shown they’re not going to do it. Workers should use our power to force the issue to the top of the agenda.”

There is an optimism that recent school student protests and blockades organised by XR have energised more people to take action. The movement has had an impact on official politics.

But it will be organising outside official politics, and activists staying mobilised, that can force real changes. The fresh new movement should not allow itself to be absorbed by the Labour Party

As Zack said, “XR has done something that I’ve never seen before in my lifetime. I think mass civil disobedience is really necessary now.”